1. Field of the Invention
The present invention relates generally to a Quality-of-Service (QoS) support method in a high-rate packet data system. In particular, the present invention relates to a method for providing QoS information to an access network.
2. Description of the Related Art
A Code Division Multiple Access 2000 (CDMA2000) system has been developed from an Interim Standard-95 (IS-95) system for chiefly supporting transmission and reception of voice signals into IS-2000 and IS-856 systems capable of transmitting and receiving high-rate data as well as voice signals. In particular, CDMA2000 1× and 1×EV-DO systems provide a function of transferring data on a packet-by-packet basis.
A communication scheme such as an existing telephone service secures a path through a previous signaling procedure with the desired party. The secured path cannot be used by other users. By transferring data through the designated path, it is possible to prevent a possible delay in a transmission section.
In the Internet Protocol (IP)-based packet communication architecture, data is transmitted with a header attached to the head thereof, instead of being transmitted after a path is previously set up, and routers forward the data to its destination based on the header information. Furthermore, in the IP-based packet communication architecture, when there is a large volume of traffic, data is transmitted in arrival order. Such a scheme for transmitting data in arrival order regardless of its traffic type is called a “Best Effort.”
The current scheme for transferring a packet via a CDMA2000 packet network is achieved by the Best Effort scheme. Such a data transfer scheme cannot guarantee transmission of real-time data for packet-based Video Telephone Service and packet-based Packet Voice Service (known as VoIP Service), for example, which will be introduced in the future. In addition, even such a data service which is insusceptible to a transmission delay is provided in different Quality of Service levels (QoSs) according to conditions of a network, thus causing users dissatisfaction. That is, the packet-based data transmission architecture disadvantageously cannot guarantee QoS in transmission of real-time data.
A QoS Support scheme for packet transmission has been introduced as a scheme for resolving such a problem.
The QoS Support scheme can be classified into an IP QoS Support scheme defined in a network layer in a CDMA2000 network, and a QoS scheme in an access network corresponding to a lower layer for supporting the IP QoS Support scheme. The IP QoS scheme has been mostly standardized by the Internet Engineering Task Force (IETF), an international standardization organization, and includes an Integrated-Service (Int-Serv) scheme and a Differentiated-Service (Diff-Serv) scheme as typical schemes.
In the Int-Serv scheme, each node desiring to transmit data sets up the necessary resources through a previous reservation procedure before transmitting data, and a Resource reSerVation Protocol (RSVP) is used as a signaling protocol for resource reservation.
In the Diff-Serve scheme, each node desiring to transmit data designates relative priority for a packet in a data header before transmission, thereby differentially processing a packet based on priority information acquired through the header.
Such an IP QoS Support method is available in an IP node. In a CDMA2000 network, the IP QoS Support method can be applied to access terminals (ATs), a packet data service node (PDSN), and several routers constituting an IP core network.
A CDMA2000 Access Network QoS scheme provides a QoS function between an access network and an access terminal, and can provide the QoS function through QoS parameters defined in an access network and a control algorithm. Therefore, in order to support an End-to-End QoS scheme, interworking between a standardized IP QoS scheme and a QoS scheme in an access network is needed. In the current 3rd Generation Partnership Project 2 (3GPP2), for End-to-End QoS Service, QoS of an access network is set between an access terminal and a packet data service node (PDSN) by transferring QoS information through RSVP, and a packet data network after the PDSN considers supporting Relative QoS by Diff-Serv.
FIG. 1 is a diagram illustrating an architecture for supporting End-to-End QoS via a CDMA2000 packet network whose standardization is currently in progress. Referring to FIG. 1, an upper application layer can acquire required QoS information by exchanging information for session setup (106), and can support IP QoS Service (107) capable of performing relative packet processing by actually reserving required resources through End-to-End QoS information transmission in an IP layer or setting a DiffServ Code Point (DSCP) value in an IP header. Such a QoS Support scheme in an IP layer must interwork with a QoS setup method (108) in an access network (AN) 102 that supports actual Bearer Service. That is, IP QoS Service (107) is a scheme that can be used between nodes performing IP communication, and a CDMA2000 packet network corresponds to an access terminal (AT) 101, a PDSN 103, and routers constituting an IP core network. The access network (AN) 102 constituting a CDMA2000 access network is not an IP node, and it supports QoS by a QoS scheme defined in a separate access network 102. Therefore, an algorithm for interworking between IP QoS and CDMA2000 Access Network QoS is required, and QoS parameters for the algorithm must be defined.
In the current CDMA2000 1× system, it is possible for an access terminal to transfer a QoS BLock-of-Bits (BLOB) representative of QoS information to a network. However, the CDMA2000 1×EV-DO system does not support a method in which an access terminal transfers a QoS BLOB representative of QoS information to a network.
In the CDMA2000 1× system, because multiple services can be distinguished using service option information, separate QoSs can be managed for separate services. However, currently, the CDMA2000 1×EV-DO system does not provide a scheme for distinguishing multiple services. Therefore, a scheme for performing separate QoSs for separate services and a scheme for distinguishing multiple services are required.